Monitoring analyses through 2012 have demonstrated that all pilot source control types are providing effective stormwater management, particularly for storms with depths of one-inch or less. In many cases, the performance of controls between 2011 and 2012 was similar. The nature of stormwater management benefits varies based upon the location and type of source control.
the report is HERE
http://www.nyc.gov/html/dep/pdf/green_infrastructure/2012_green_infrastructure_pilot_monitoring_report.pdf